The norhis peters co



(No Model.) 2 Sheets-Sheet 1.

R. L.' SHORT.

PURNAGB. l No. 605,753l Patented June 14, 1898.

(No Model.)

2 Sheets-Shelet;l 2, R. L. SHORT.

PURNAGB. No. 605,753. Patented June 14,1898.

4vih r 1 ATTEST INVENEFF.

Y H. y my UNITED STATES- PATENT Orricn.

ROBERT L. SHORT, OF CLEVELAND, OHIO, ASSIGNOR TO THE GARTLAND FOUNDRY COMPANY, OF SAME PLACE.

FU RNACE.

SPECIFICATION forming part of Letters Patent No. 605,753, dated J une 14, 1898.

' Application tied rune 3,1897. semina 639,264.. (No man.)

T all whom t may concern:

Be it known that I, ROBERT L. SHORT, a

citizen of the United States, residing at Cleve-v land, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Furnaces; and l do declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the'art to which it appertains to make and use the same.

JMy invention relates to heating-furnaces; and the invention consists in a heating-furnace constructed and operating substantiallyr as shown and described, and particularly pointed out in the claims.

ln the accompanying drawings,Figure l is a longitudinal sectional elevation of my improved furnace corresponding to line 2 2, Fig. 2. Fig. 2 is a cross-section of the furnace, taken on a line corresponding substantially to 3 3, Fig. l, and looking to the rear. Fig. 3 is a perspective elevation of the upper section or half of the furnace, and Fig. 4 is a perspective elevation of the lo'wer sectionthereof, these two sections constituting the body of the furnace, which is divided horizontally into upper and lower heat-chambers, as hereinafter described. Fig. 5 is a perspec- .tive view of one of the grate-bars; and Fig. 6

is a longitudinal section, enlarged, of the front end of one of said bars. Y

The object of this invention is, rst, to provide a furnace which will radiate or give off to the air for heating the dwelling or other place the largest percentage practicable of all the heat generated and so that there will be the least possible loss of heat by reason of bad or defective construction. The next and no less important object is to provide l'a furnace in which the cheapest grades or qualities of coal-such, for example, aswhat is known as slack or any other cheap fuel of this kind-- can be successfully used in lieu of more expensive coal, hard or soft, or coke, or the like.

To these several ends the furnace is fashioned, as shown, with a body consisting of two horizontal and substantially equal sections or parts A and B, Figs.-3 and 4, in which the said sections are shown separately, so as tovmore clearly disclose their construction. The s ection B is thebase or lower section, and the internal construction thereof, which is not seen in Fig. 4t, is disclosed in Fig. l. ticed that said base-section B is designed to rest over the fresh-air pit or well, as seen in Fig. 4, so that the air passages or tubes 2, extending vertically through said section from bottom to top, receive their supply of air from the air-well, as usual.

The peculiarities of construction of the base-section B are seen most clearly in Fig. l, and consist of an ash-box 3, open all over from the top and having a depth and length equal to about one-third of the said section in depth and length, respectively. The front door 4 has a damper, as usual'in such doors. In thisstyle'of furnace an ash-pan is generally used, but not shown here. A further peculiarity of this base-section is the air-chamber 5` just at the rear of the ash-box and across the full width thereof and the air-supply or draft pipes or tubes 6, which enter said box across the opening in the rear of section B for the downdraft from the irechamber, as hereinafter more fully described. At their outer ends said tubes or pipes 6 extend through the rear wall of section B and the inclosing drum D, so as to get the airsupply to the lire, substantially as shown, the air passing from these tubes tov the chamber 5 and distributing thence to and through the tubular grate-bars 10 to the tire-chamber.

A further feature of base-section B is the arrangement for carrying off the products of combustion through the bottom of the base and consisting of the ue E, the front ends of which project well to the front of said basesection beneath the ash-box, so that the freshair tubes 2 will be exposed to the current and volume of heat from rear to front of the furnace before the heat can enter on its escapepassage from the furnace. This exposes all said iiues 2 fully to the heat beneath the ashbox and makes said ilues available for heating the air, and thus at last practically all the heat generated by the furnace is absorbed by the lues 2 before it ultimately gets to the place of discharge.

In its travel to the iiue or passage E the heat frdm the furnace necessarily passes directly over the tubes 6, which traverse the downdraft-passage a, so that here the air It will be no- IOO which feeds combustion is initially heated bcfore it enters the chamber 5, where further heating occurs as it passes into the highlyheated bars lO. Finally, it will be seen in Fig. I that the entire top of lower section l5 is covered or inelosed about the top of airtubes 2, so that there is no downdraft from the combustionchamber about said tubes nor anywhere except through the rear passage a directly in rear of the fire-chamber.

The upper section A of the furnace is constructed to rest iiat upon the base-section B and has air-tubes 2 in position to match the tubes l below, as seen in Fig. 2, and is closed about said tubes. The fire-box l) is formed in this upper section and has a doorF, through which fuel is supplied, and a direct fiue connection 8 to the smoke-stack to be used especially in starting a fire. Ordinarily this flue is closed and the outlet is through iiue E.

The grate-bars C are each formed in two sections longitudinally and are tubular or hollow from end to end, so as to carry a full supply of fresh air in sufficient quantity to meet all the demands of the furnace for complete combustion. i Said tubes are placed more closely together side by side than gratebars in furnaces ordinarily are located to enable the furnace to utilize slack coal, which often comes in Very finely-divided particles. At their front ends said bars are turned upward and forward, so as to discharge the air over the bed of the fuel and sustain combustion from the top of the fuel instead of from or through the bottom. IIence when the furnace is going the entire air-supply comes through these flues or grate-bars and none is admitted through the ash-pit, and henee,also, only superheated air is brought into the furnace. Another peculiarity of these gratebars is that they are built with greater surface width in their front half than in their rear, the present bar having a flange lO longitudinally along its top at each side extending about half the length of the bar. This enables Very fine coal to be fed onto the front of the grate, where all fresh coal is lodged, without danger of its creeping through into the ash-pan. Here the fresh coal is allowed to remain until it roasts and cokes and the gas rising from it isconsumed. Then as the coal thus roasted is reduced practically to a coke it is pushed back onto the rear half of the grate, which is more open, and through which the ashes pass below. In this way I avoid bringing fresh coal to the fire, whiehis at the rear of the fire-chamber, and hence avoid chilling the fire as well as producing excessive smoke. Furthermore, since I draw my air-supply for supporting combustion entirely through the grate bars or tubes, I so superheat the air that it is in condition to combine at once with the liberated gases in the front of the furnace, and as these gases have to pass over the lire at the rear they necessarily are ignited and consu med. This also works material economy of fuel,because a relatively small percentage of combustible matter escapes combustion in the furnace and correspondingly less coal is required. This would not be possible if the fresh coal were thrown directly upon the fire, as is common in furnaces, and especially would it not be possible if the air were not heated and delivered over or onto the fuel instead of drawing it between the grate-bars from the ash-pit.

The fire-box is built apart from the side air-tubes 2, so that these tubes are not in the path of the llame as it travels to the downexit a, and hence are not exposed directly to the flame, but are heated by radiation. The hottest point in the furnace, therefore, is directly over and rear of the hot-air box 5, and thence the heat passes below to be further taken up by the lower section of the freshair tubes 2. In this way the entire length of these exceptionally long tubes is exposed to the heat, and I am enabled to obtain two hundred or more feet of radiating-surface in a furnace adapted to an eight or nine room house as compared with seventy or eighty square feet in like-sized furnaces with which I am acquainted. Then, again, by keeping the fiame away from tubes 2 I do not burn and kill the fresh air and do not burn out the furnace, as occurs when the air-tubes are exposed directly to the iame.

In operation the draft is through the pipes 6, chamber 5, and grate-bars C into the hrechamber over and upon the fuel, and thence back and down through passage c into the lower chamber of the furnace and forward past the air-tubes 2 to the mouth of the outlet-flue By this construction and coperation of parts novel results are obtained. First, I am enabled to burn slack coal as suecessfully as any other coal for domestic heating, thus working great economy in the price of fuel. Secondly, I eliminate and utilize a much greater percentage of the heat generated by reason of my downdraft and long line of travel of heat amid the fresh-air tubes as compared with all upper or side draft furnaces. Thirdly, the location of the draftsupply pipes G in the path of the products of combustion from the fire-chamber enables me to so heat the air that it readily combines with the gases in the furnaces and thus promotes perfect combustion.

l. In hotair furnaces, a furnace -body formed in two horizontal sections, fresh-air tubes in each section extending the full depth of the sections and matching to make continuous passages, a horizontal diaphragm about said ilues to cut off downdraft about them, a downdraft-opening in the rear of the furnace and an exit for the products of combustion leading from the bottom section of the furnace near its front, whereby the outgoing heat reaches the fresh-air ilucs in the bottom of the furnace and is absorbed, substantially as set forth.

2. The furnace -casing consisting of two IOO IIO

horizontal sections, fresh-air tubes extendingv through both sections in series along both sides thereof and a horizontal diaphragm between said sections closing the downdraft about said tubes and leaving a draft-openin g for the products of combustion from the upper to the lower section, av iire-box in said upper section having side walls to protect the fresh-air lines, and an ash-pit in the lower section, and an exit for the products of combustion having its entrance in the end of the said lower section opposite said downdraft, whereby the fresh-air tubes in the lower section are heated and the heat is taken up, substantially as set forth.

3. In air-heating furnaces, a furnace-body having fresh-air flu'es extending vertically through the same and open at both ends, a fire-chamber between said flues and apart therefrom and adowndraft at the rear of the furnace whereby the flame is kept from said tubes, and tubular grate-bars at the bottom of said chamber constructed to d'ischarge into said heat-chamber at their front ends over the fuel, in combination with air-supply connections with the rear ends of said grate-bars traversing the said downdraft from the firechamber, whereby the air entering the gratebars is heated and fed over the fuel, substantially as described.

4. In air-heating furnaces, the body of the furnace having fresh-air flues through from bottom to top and a horizontal division between said uesy midway their elevation to cut off downdraft about said tubes and having a downdraft-passage centrally at its rear, and an exit-iiue in its bottom having its mouth at the front of the furnace, in combination with air-supplyin g grate-bars-constructed and arranged to discharge air over the fuel in the furnace, and air-supply connections for said grate-bars directly exposed to the outgoing heat from the furnace, substantially as described.

5. In air-heating furnaces, the body consisting of two separate sections placed one on top of the other and having air-iiues passing vertically through them, said sections closed horizontally about said tubes midway their elevation, the exit-flue in the lower section having its mouth in the front of the furnace, the nre-chamber in the upper section and the hollow grate-bars at the bottom of said chamber constructed to carry finely-divided coal and to discharge air over the coal at their front ends, and a draft-passagefor the products of combustion with the furnace and airsupply connections for said hollow grate-bars exposed to said draft-passage, whereby the air entering the grate-bars is heated, substantially as described.

6. In heating-furnaces, a furnace-body having upper and lower horizontal chambers and a down-passage at its rear from one chainber to the other, a iire-box in the upper chamberv and an exit-ue in the lower chamber and fresh-air flues extending along its sides through both chambers, in combination with a grate for said fire-box consisting of hollowv 

